Artificial crown for teeth and securing means therefor



De'c. 1924- 1,517,500

E. M. FREDERICKS I ARTIFICIAL CROWN FOR TEETH ND SECURING MEANS T HEREFOR Filed Jan. 5, 1924 Patented Dec. 2, 1924.

UNITED STATES PATENT QFFICE.

ENOCH M. FREDERICKS, OF CHICAGO, ILLINOIS.

ARTIFICIAL CROWN FOR TEETH AND SECURING MEANS THEREFOR.

Application filed January in the means for securing the same, of a type somewhat similar to that disclosed in Letters Patent of the United States bearing Numbers 900,363, and 1,418,070, issued to me on October 6, 1908, and on May 30, 1922, respectively.

The present invention has for its principal object to greatly improve the construction and efficiency of tooth crowns and the securing means therefor made according to my aforesaid Letters Patent, as well as over all other tooth crowns and securing means therefor, whereby the breakage of the crowns after being mounted will be reduced to a minimum; turning of the crowns on their supporting posts during mastication will be prevented; facility and security in mounting the crowns increased, and the amount of labor and time expended in fitting the crowns to or mounting them upon the natural roots of the teeth will be reduced.

Other objects andadvantages of the invention will become apparent from the following description and explanation, which will be more readily understood when read in conjunction with the accompanying drawing, in which embodiments of which the in-' vention is susceptible'is illustrated, it being understood vthat changes and alterations therein may be resorted to without departing from the spirit of the invention, so long as they fall within the scope of the appended claims forming a parthereof.

In the drawing, the views are greatly exaggerated.

Fig. 1 is a plan view of a tooth crown equipped with fastening means arranged and constructed according to my present invention.

Fig. 2 is a vertical sectional view taken on line 22 of Fig. 1 looking in the direction indicated by the arrows showing the crown secured to a natural tooth root.

Fig. 3 isa detached view in side elevation of a crown supporting post employed as 5, 1924. Serial No. 684,518.

part of the securing means of my present invention.

Fig. 1 is a fragmental sectional view'of a part of the crown equipped with one form of a metallic shell or lining for the cavity of said crown. v

Fig. 5 is a detached longitudinal sectional view of said metallic shell or lining, and

Fig. 6 is a similar View of a modified form of the shell or lining. I

Corresponding numerals of reference refer to like parts throughout the different views of the drawing.

Referring now more particularly to Fig.

2 the reference numeral 7 designates a portion of the root of a natural tooth in a bore or cavity of which is secured by means of cement 8 or otherwise a supporting post for the crown, designated as a whole by the numeral 9 which may be made with an upwardly tapered shank 10 provided with spurs or projections 11 to engage the cement in the cavity of the root. This post may be made of any suitable size and material, and as is clearly shown in Fig. 3 of the drawing, has at its lower end an upwardly tapered portion 12 which terminates V at the lower end of a cylindrical part 13 of the post. Just above the cylindrical part 13 of the post, the latter is provided with an annular flange or shoulder 14 which preferably has, its surface adjacent the shank portion 10 of the post flat or substantially so while the opposite or lower surface of the flange or shoulder 14: is preferably rounded as is clearly shown in Figs. 2 and 3 of the drawing. The shoulder or flange 14 is provided with one or more grooves or recesses 15 which communicate at their lower ends r with one or more longitudinally disposed grooves or recesses 16 with which the cylindrical portion 13 of the post is provided. As shown in the drawing, the shoulder 14 is provided with a pair of diametrically disposed grooves 15 while'the cylindrical portions 13 of the post is provided with a pair of diametrically disposed grooves 16 re istering with the grooves of the Sl10uld81,%ut it will be understood that I do not desire to limit myself to the above mentioned disposition of the grooves or to the above mentioned number in each of the parts of the post, but may employ one or more registering grooves in the said shoulder and the cylindrical part 13 without a departure from the invention.

By reference to Fig. 1, it will be seen that '2 f V V 7 1,517,500

the shoulder l t elongated for an important purpose to be presently explained.

,The artificial tooth crown is designatedas a Whole by the numeral17 and may be made of any sultable shape and size in accordance with the positionfin the mouth in which it is to be placed and is, preferably formed oi porcelain, but may be made of any other suitable material. The upper surfaceofthe crown is substantially flat as shown in Figs. 1 and 2and is-provided centrally with a cavity 18 of a shape to correspond with the; shoulder or flange 14; on the crown supporting post.,9 and of sufficient ,depth to receivesaid shoulder or flange in such'a way'that its'uppersurface will be about.

. flushjz with the upper surface ofthe crown or that surface thereofadja'centthe root I 7 to which ityis tobe securejds l-Molded'in the usual manner, or in any preferred 1 way 1 in the crown, and centrally with respect to the-cavity l8 thereofisa shell 19 which is preferably made of --platinum, butnray be mad'e of anyother suitable refractory ma terial. 1 As shown, this shell is truncated coniealin ."shape, and .has its upper end.

open,.and-'when in p1ace in the, cavity-there- V for; inthecroWn, forms a lining for the walls thereof as well as means for preventmg portions orparticles of the porcelain or V .rnaterialout of which'the crown 17 is made falling-into thef shell during the process of molding theshellin the crown. This meansfconsists of an outwardly extended annrrlar flangeflQO with which the upper end of thee lindricalfneck j21 of. the shell 19 isprovi ed; :Thi's flange is of less width i j rhannthe-width,ofitheicavity; or recess 18 fromthe upper end ofthe cylindrical; neck portion 21 .oftheshell "or lining, that is to saygthe outer edge 'o'f the flange 2O terminates -onthe floor" of the cavity 18 short of, theupwardly ex'tended walls of lsaid cavity: as'will be readily understood; by reference to Figs, 2; and'l4 of the drawing. Erdmits cylindrical neck portion 21the shell19' is? downwardly enlarged and asbeforeqstated, hasfits bottom "or inner end closed. 7 The cylind'rical neck: portion 21 of theJshell is; ofsufiicient size to fit closely around T the cylindrical portion 13'v vof the crown supporting post andisprovided in.

its inner surface with a number [of grooves 22,-fcorrespondingin number and position with-the grooves 16in the 'cylindrical'part 13 0f sai'dp'ostQ a The grooves 22- are longitudinally disposed in theneck portion 21 of the shell and each communicates at its outer end with a laterally disposed groove 23 formed in the upper-pr outer; surface of the flange 20-as is clearly shown in Figs. 5 and '6 offthe drawing. The tapered portion 12 of the crown, supporting post 9 is at its largest part of a size to fit snugly in the opening neck portion '21 df theshell, but so as to permit said tapered portion to be extended through said opening and pos1- tioned Within the tap red part of the'shell,

with its free .endspaced a slight distance from thebottom ofsaid shell. When thus positioned, it is manifest that the shoulder 14 will rest on the outer surface of the'flange 20 and that the cylindrical; portion .13 of the post will be snugly'gfitted in the opening ofthe cylindrical -neck '1 portion 21 of the shell, which arrangement will so support the post as to prevent thepossibilityror tendency of any lateral movement; crane latter. By providing the shell and its flange with the grooves 22 and 23 and by furnishing the cylindrical portion 13 and shoulder la of the post with the grooves 16 and 15 respectively, it is apparent that means will'be provided for the escape of air and the tapered portion of, the post is positioned about as shown in Fig. 2 ofthe drawin in which -;vi ew aswell as inFig. 1, 1t' W11 be seen and understood that'the cavity in which the shoulder or flange 1 t is seatedi'is slightly larger than said shoulder, which 185 excess of cement 8 fromithe' shell when the arrangement will permit the excess "cement from the shell 19 to enter the space between pressure, is applied theretoin mastication, yet I may-make the shoulder li and the recess 1'8tl1'erfor of other shapes'than I cular and attain the sameresult, of prevent ing rotation of the crown on its post.

prevented turning onthe post when uneven 1 1 Instead of 'formin theshell l9fwith a bottom as showniin igs. 2,4 and 5 of thedrawing, I may form it without a" bottom as illustrated iniFig. '6,and attain substhu 'tially' the same results as by the use-of the above described construction. While I have describedthe partsas, if they were employed in a tooth crown to be fitted to theupperjaw andi have soill1iS- trated it 'in' the "drawing, yet it will be understood that when employed for a crown to be used on'the lowergaw the descriptive terms, will be} reversed, for' example, the

shank 10 ofthe; post will constitute its lower portion andiFthe-ta'pere d portion 1'2: its upper portion instead of as shown and above described." l

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. As an article of manufacture, an artiflcial tooth crown having a post-receiving cavity therein, said cavity terminating at its outer end in a recess or chamber, and a metallic shell located in said cavity and having at its outer end an external flange overlying and engaging the wall of said recess.

2. As an article of manufacture, an artificial tooth crown having a recess of a shape other than a true circle in its surface adjacent the root or base on which it is mounted, and a tapered metallic shell molded in the crown and presenting its contracted portion outwardly, said contracted portion having an external flange engaging the wall of said recess.

3. The combination with a tooth crown having a post-receiving cavity therein, said cavity terminating at its outer end in an encompassing recess or chamber of a shape other than a true circle, of a metallic shell located in said cavity against the walls thereof and having on the outer surface of its smaller end a flange engaging the wall of said recess and on the inner surface of its smaller end one or more longitudinally extending grooves, and a securing post located at one of its ends in the shell and having a shoulder corresponding in shape to the shape of said recess and located in said recess and on the flange of said shell.

4. The combination with a tooth crown having a post-receiving tapered cavity therein, said cavity terminating at its outer end in an encompassing recess or chamber of a shape other than a true circle, of a tapered metallic shell located in said cavity against the walls thereof and having on the outer surface of its smaller end a flange engaging the wall of said recess and on the inner surface of its smaller end one or more longitudinally extending grooves, said flange having on its outer surface one or more grooves in communication with the first named grooves, a securing post located at one of its ends in the shell and having a portion within the shell tapered from its free end towards the contracted end of the shell and provioed with a shoulder corresponding in shape to the shape of said recess located in said recess and on the flange of said shell.

5. The combination with a tooth crown having a post-receiving tapered cavity therein, said cavity terminating at its outer end in an encompassing recess or chamber, of a tapered metallic shell located in said cavity against the walls thereof and having on the outer surface of its smaller end a flange engaging the wall of said recess and provided below said flange and adjacent thereto with a cylindrical neck portion, and a securin postloeated at one of its ends in the shell and having a portion within the shell tapered from its free end towards the contracted end of the shell and provided with a shoulder corresponding in shape to the shape of said recess located in said recess and on the flange of said shell, said post having below and adjacent said shoulder a cylindrical portion.

ENOOH M. FREDERICKS. 

